Method for measuring laminated iron core

ABSTRACT

There is provided a method for measuring a laminated iron core. The method includes preparing a laminated iron core in which two or more kinds of metal plates with different shapes are laminated and a deformed part is formed inside a hole continuing in a lamination direction of the laminated iron core, acquiring a surface profile data indicating a surface shape of the deformed part through an inlet of the hole by a non-contact sensor located in an outside of the hole, and calculating a length from the inlet of the hole to the deformed part in the lamination direction by a calculator based on the surface profile data.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of the non-provisional applicationSer. No. 15/493,590, filed on Apr. 21, 2017 which was filed based uponand claims the benefit of priority of Japanese Patent Application No.2016-087955 filed on Apr. 26, 2016, the contents of which areincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a method for measuring a laminatediron core.

2. Description of the Related Art

A laminated iron core is a component constructing a motor (electricmotor), and forms a rotor or a stator of the motor. The laminated ironcore is obtained by stacking a plurality of metal plates (blankedmembers) blanked from an electromagnetic steel plate in a predeterminedshape and interlocking the metal plates. A coil is wound on a statorlaminated iron core forming the stator. A shaft and a permanent magnetare installed in a rotor laminated iron core forming the rotor.Thereafter, the stator and the rotor are combined to complete the motor.The motor adopting the laminated iron core is used as, for example,driving sources of a refrigerator, an air conditioner, a hard diskdrive, an electric power tool, a hybrid car, an electric vehicle, etc.

The laminated iron core is generally manufactured by a forward die unit.A step of intermittently blanking a strip-shaped electromagnetic steelplate and obtaining a blanked member and a step of stacking theplurality ofity of blanked members to a predetermined laminationthickness and obtaining a laminated iron core are performed inside theforward die unit. The laminated iron core ejected from the forward dieunit requires that the thickness (lamination thickness) of the laminatediron core should be within a predetermined tolerance. However, a platethickness of the strip-shaped electromagnetic steel plate is not alwaysuniform. That is, the strip-shaped electromagnetic steel plate has adeviation of the plate thickness. As a result, there are cases where thethickness of the laminated iron core is not within the tolerance underthe influence of the deviation of the plate thickness in the case ofsimply laminating a predetermined number of blanked members.

JP-A-11-55906 as Patent Literature 1 discloses a method formanufacturing a laminated iron core having a counter bore in which ashaft hole is provided with a step. The laminated iron core described inJP-A-11-55906 is constructed by combining two or more kinds of blankedmembers with different shapes. The manufacturing method described inJP-A-11-55906 uses a control program for correcting the number oflaminations by specifying one of the counter bores excluding the counterbore in which the number of laminations is specified. JP-A-2010-263757as Patent Literature 2 discloses a laminated iron core in which arefrigerant flow path is formed inside a shaft hole as another exampleof the laminated iron core constructed by combining two or more kinds ofblanked members with different shapes. Note that, in the presentspecification, the laminated iron core in which two or more kinds ofblanked members with different shapes are laminated and a deformed partsuch as a projection, a recess or a hole is formed inside a holecontinuing in a lamination direction (axial direction) may be called a“laminated iron core with deformed part”.

Patent Literature 1: JP-A-11-55906

Patent Literature 1: JP-A-2010-263757

SUMMARY OF THE INVENTION

In the laminated iron core described in JP-A-11-55906 orJP-A-2010-263757, etc., it is decided whether or not the deformed parthas a desired size by using the number of laminations of the blankedmembers. However, in recent years, a demand for high quality of thelaminated iron core has increased more, and it is desirable to acquirethe size of the deformed part with high accuracy.

Hence, the present disclosure describes a method for measuring alaminated iron core capable of acquiring a size of a deformed part withhigh accuracy.

(1) A method for measuring a laminated iron core according to an aspectof the present disclosure includes: preparing a laminated iron core inwhich two or more kinds of metal plates with different shapes arelaminated and a deformed part is formed inside a hole continuing in alamination direction of the laminated iron core; acquiring a surfaceprofile data indicating a surface shape of the deformed part through aninlet of the hole by a non-contact sensor located in an outside of thehole; and calculating a size of the deformed part by a calculator basedon the surface profile data.

The hole continuing in the lamination direction of the laminated ironcore is generally small to the extent to which it is difficult for acontact sensor to enter the inside of the hole, and the deformed part ofthe inside of the hole cannot be measured by the contact sensor.However, in the method for measuring the laminated iron core accordingto one aspect of the present disclosure, the non-contact sensor locatedin the outside of the hole acquires the surface profile data indicatingthe surface shape of the deformed part through the inlet of the hole. Asa result, the non-contact sensor directly acquires the surface profiledata of the deformed part from the outside of the hole without facingthe deformed part. Also, in the method for measuring the laminated ironcore according to one aspect of the present disclosure, the calculatorcalculates the size of the deformed part based on the surface profiledata. Thus, in the method for measuring the laminated iron coreaccording to one aspect of the present disclosure, the size of thedeformed part is directly acquired using the non-contact sensor ratherthan the number of laminations of the metal plates. Consequently, thesize of the deformed part can be acquired with high accuracy.

(2) In the method for measuring the laminated iron core according to themethod (1), the surface profile data indicating the surface shape of thedeformed part may be acquired by the non-contact sensor located in theoutside of the hole through the inlet of the hole, with the laminatediron core pressurized in the lamination direction.

A finished product of the laminated iron core may be obtained bycompletely bonding the mutual blanked members by welding etc. with thelaminated iron core pressurized in the lamination direction after thelaminated iron core is measured. In this case, a size equal to that ofthe deformed part in the finished product can be acquired by acquiringthe surface profile data with the laminated iron core pressurized in thelamination direction as described above.

(3) The method for measuring the laminated iron core according to themethod (1) or (2) may be configured such that the non-contact sensor isa non-contact laser displacement meter, and the surface profile dataindicating the surface shape of the deformed part is acquired by thenon-contact laser displacement meter located in the outside of the hole,which applies laser light from the inlet of the hole to the deformedpart and receives reflected light of the laser light.

(4) The method for measuring the laminated iron core according to anyone of the methods (1) to (3) may be configured such that the deformedpart is a projected part projected from a peripheral surface of the holein an intersection direction intersecting with the lamination direction.

(5) The method for measuring the laminated iron core according to anyone of the methods (1) to (3) may be configured such that the deformedpart is a branched hole continuing from a peripheral surface of the holein an intersection direction intersecting with the lamination directionso as to be branched from the hole.

(6) The method for measuring the laminated iron core according to anyone of the methods (1) to (5) may further include moving or rotating oneof the laminated iron core or the non-contact sensor with respect to theother of the laminated iron core and the non-contact sensor.

In this case, one of the laminated iron core and the non-contact sensoris moved or rotated with respect to the other of the laminated iron coreand the non-contact sensor, with the result that the non-contact sensoracquires the surface profiles of the plurality of deformed parts at oncewhen the laminated iron core is provided with the plurality of deformedparts. As a result, the sizes of the plurality of deformed parts can beacquired at once with high accuracy.

(7) The method for measuring the laminated iron core according to anyone of the methods (1) to (6) may be configured such that a length ofthe deformed part in the lamination direction is calculated by thecalculator based on the surface profile data.

(8) The method for measuring the laminated iron core according to anyone of the methods (1) to (6) may be configured such that a length ofthe deformed part in a circumferential direction of the hole iscalculated by the calculator based on the surface profile data.

(9) The method for measuring the laminated iron core according to anyone of the methods (1) to (8) may be configured such that a length fromthe inlet of the hole to the deformed part in the lamination directionis calculated by the calculator based on the surface profile data.

(10) The method for measuring the laminated iron core according to anyone of the methods (1) to (9) may be configured such that the deformedpart is a projected part projected from a peripheral surface of the holein an intersection direction intersecting with the lamination direction,and a projection length of the projected part is calculated by thecalculator based on the surface profile data.

(11) A system for measuring a laminated iron core according to an aspectof the present disclosure includes: a controller; a pinching platepinching a laminated iron core in which two or more kinds of metalplates with different shapes are laminated and a deformed part is formedinside a hole continuing in a lamination direction of the laminated ironcore, the pinching plate including a through hole; a non-contact sensorlocated in an outside of the through hole of the pinching plate, thecontroller acquiring a surface profile data indicating a surface shapeof the deformed part through an inlet of the hole of the laminated ironcore and the through hole of the pinching plate by the non-contactsensor, and calculating a size of the deformed part based on the surfaceprofile data.

The method or system for measuring the laminated iron core according tothe present disclosure can acquire the size of the deformed part withhigh accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a perspective view showing one example of a rotor;

FIG. 2 is a sectional view taken on line II-II of FIG. 1;

FIG. 3 is a sectional view taken on line III-III of FIG. 1;

FIG. 4 is an explanatory diagram of one example of a method formeasuring a deformed part;

FIG. 5 is an explanatory diagram of one example of the method formeasuring the deformed part;

FIG. 6 is an explanatory diagram of another example of a method formeasuring a deformed part;

FIG. 7 is an explanatory diagram of a further example of a method formeasuring a deformed part;

FIG. 8 is an explanatory diagram of a further example of a method formeasuring a deformed part;

FIG. 9 is a perspective view showing another example of a laminated ironcore;

FIG. 10 is a perspective view showing a further example of a laminatediron core; and

FIG. 11 is a perspective view showing a further example of a laminatediron core.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

An embodiment according to the present disclosure described below is anillustration for describing the present invention. Thus, the presentinvention should not be limited to the following embodiments orcontents. In the following description, the same reference sign ornumeral is used for the same element or an element having the samefunction, and overlap description is omitted.

(Configuration of Rotor)

First, a configuration of a rotor 1 will be described with reference toFIGS. 1 to 3. The rotor 1 constructs a motor (electric motor) togetherwith a stator. The rotor 1 includes a laminated iron core 10, aplurality of permanent magnets 12, a plurality of resin materials 14,and a shaft (not shown).

The laminated iron core 10 is a laminated body formed by laminating aplurality of blanked members 20 (metal plates) formed by blanking astrip-shaped electromagnetic steel plate (not shown). The laminated ironcore 10 has two or more kinds of blanked members 20 with differentshapes. The blanked members 20 are mutually bonded by caulking, welding,etc.

The laminated iron core 10 has a circular cylindrical shape. That is,the center of the laminated iron core 10 is provided with a shaft hole10 a pierced in the laminated iron core 10 so as to be continuous alonga central axis Ax. That is, the shaft hole 10 a continues in alamination direction (hereinafter simply called a “laminationdirection”) of the laminated iron core 10. The lamination direction isalso an extension direction of the central axis Ax. A shaft is insertedinto the shaft hole 10 a.

The laminated iron core 10 is formed with a plurality of magnet-insertholes 10 b and a plurality of deformed parts 10 c. The magnet-insertholes 10 b are arranged at predetermined distances along an outerperipheral edge of the laminated iron core 10 as shown in FIG. 1. Themagnet-insert holes 10 b are pierced in the laminated iron core 10 so asto continue or be continuous along the central axis Ax as shown in FIG.2. That is, the magnet-insert holes 10 b continues in the laminationdirection.

The shape of the magnet-insert hole 10 b is an elongate hole continuingalong the outer peripheral edge of the laminated iron core 10 in theembodiment. The number of magnet-insert holes 10 b is sixteen in theembodiment. Positions, shapes and the number of magnet-insert holes 10 bmay be changed depending on, for example, required performance or use ofthe motor.

The inside of the magnet-insert hole 10 b is provided with a pluralityof projections 10 d. The projection 10 d is projected along a radialdirection (hereinafter simply called a “radial direction”) of thelaminated iron core 10 outwardly from a surface (an inside innerperipheral surface) near to the central axis Ax in an inner peripheralsurface of the magnet-insert hole 10 b. That is, the projection 10 dextends in an intersection direction (radial direction) intersectingwith the lamination direction outwardly from the inside inner peripheralsurface. The projections 10 d are arranged at predetermined distances inthe extension direction (lamination direction) of the magnet-insert hole10 b.

The deformed part 10 c is arranged inside the shaft hole 10 a. Thedeformed part 10 c is a recessed part recessed from an inner peripheralsurface of the shaft hole 10 a toward the radial outside as shown inFIG. 3. That is, the deformed part 10 c extends in the radial directionoutwardly from the shaft hole 10 a. The deformed part 10 c of theembodiment is one form of a branched hole radially continuing from theinner peripheral surface of the shaft hole 10 a so as to be branchedfrom the shaft hole 10 a.

The shape of the deformed part 10 c is a rectangular shape when viewedfrom the radial direction in the embodiment. The number of deformedparts 10 c is two in the embodiment, and a pair of the deformed parts 10c is positioned symmetrically with respect to the central axis Ax. Theshapes and the number of deformed parts 10 c may be changed accordingto, for example, required performance or use of the motor.

The permanent magnet 12 is inserted into the magnet-insert hole 10 b asshown in FIGS. 1 and 2. The permanent magnet 12 is pinched by theprojection 10 d and a surface (an outside inner peripheral surface) nearto the outer peripheral edge of the laminated iron core 10 in the innerperipheral surface of the magnet-insert hole 10 b inside themagnet-insert hole 10 b as shown in FIG. 2. The number of permanentmagnets 12 inserted into the magnet-insert hole 10 b may be one or more.The plurality of permanent magnets 12 may be arranged in acircumferential direction of the laminated iron core 10 or in thelamination direction inside the magnet-insert hole 10 b. A kind ofpermanent magnet 12 could be determined according to, for example,required performance or use of the motor, and may be a sintered magnetor a bonded magnet.

The inside of the magnet-insert hole 10 b after the permanent magnet 12is inserted is filled with the resin material 14. The resin material 14has a function of fixing the permanent magnet 12 into the magnet-inserthole 10 b. The resin material 14 includes, for example, a thermosettingresin. A concrete example of the thermosetting resin includes, forexample, a resin composition including an additive, a curing initiator,and an epoxy resin. The additive includes, for example, a filler, aflame retardant or a stress relaxation agent. The resin material 14mutually bonds the blanked members 20 adjacent in a vertical direction.In addition, a thermoplastic resin may be used as the resin material 14.

(Method for Measuring Laminated Iron Core)

Subsequently, a method for measuring the laminated iron core 10 will bedescribed with reference to FIGS. 4 and 5. First, as shown in FIG. 4,the laminated iron core 10 is pinched in the lamination direction by apair of pinching plates 30, 32. Accordingly, the laminated iron core 10is pressurized in its lamination direction by the pinching plates 30, 32to the extent to which the adjacent blanked members 20 make closecontact with each other. The pressure applied to the laminated iron core10 by the pinching plates 30, 32 can have various intensities dependingon the size of the laminated iron core 10, and may have, for example,the intensity in which a thickness T of the laminated iron core 10 afterpressurization satisfies values from 99.9% of a thickness T₀ (inclusive)of the laminated iron core 10 before pressurization to the thickness T₀(exclusive) (0.999T₀≤T<T₀). In the embodiment, the pinching plate 30abuts on one end face (upper surface of FIG. 4) of the laminated ironcore 10, and the pinching plate 32 abuts on the other end face (lowersurface of FIG. 4) of the laminated iron core 10.

An actuator 34 is connected to the pinching plate 30 through a shaft 34a extending along the central axis Ax. The actuator 34 drives and stopsrotation according to a driving signal from a controller 36(calculator). The center of the pinching plate 32 is provided with athrough hole 32 a larger than the shaft hole 10 a. With the laminatediron core 10 pinched by the pinching plates 30, 32, the through hole 32a communicates with the shaft hole 10 a.

Next, a non-contact sensor 38 is prepared. Concretely, the non-contactsensor 38 is arranged under the through hole 32 a of the pinching plate32 so that a sending and receiving part for a detection signal faces tothe side of one deformed part 10 c targeted for detection through aninlet of the shaft hole 10 a. That is, the non-contact sensor 38 islocated in the outside of the shaft hole 10 a. As the non-contact sensor38, various sensors can be used as long as a surface profile dataindicating a surface shape of an object to be measured can be acquiredwithout contact with the object to be measured, and the non-contactsensor 38 includes, for example, a non-contact laser displacement meteror an ultrasonic displacement meter. The non-contact laser displacementmeter includes a light source for emitting laser light, and a lightreceiving element for receiving reflected light, and calculates adistance to the object to be measured based on, for example, an imagingposition or the amount of light in the light receiving element. Theultrasonic displacement meter includes a wave sender for sendingultrasonic waves, and a wave receiver for receiving the reflected waves,and calculates a distance to the object to be measured based on the timetaken to receive the ultrasonic wave since the ultrasonic wave is sent.

Then, the controller 36 sends a driving signal to the non-contact sensor38, and sends, for example, a detection signal diffused in thelamination direction from the non-contact sensor 38, and the non-contactsensor 38 receives a reflected signal of the detection signal andthereby, the non-contact sensor 38 is made to acquire a surface profileof the deformed part 10 c. In the embodiment, the laminated iron core 10is rotated, with the result that the non-contact sensor 38 acquires asurface profile data of an inner peripheral surface of the shaft hole 10a in addition to the surface profile data of the deformed part 10 c. Thesurface profile data (or simply called “surface profile”) acquired bythe non-contact sensor 38 is sent to the controller 36. FIG. 5 shows oneexample of a surface profile P of the deformed part 10 c acquired by thenon-contact sensor 38.

The surface profile P shown in FIG. 5 as one example includes linesegments P1 to P6. The line segment P1 corresponds to an innerperipheral surface of the through hole 32 a, and extends in a verticaldirection of FIG. 5. The line segment P2 corresponds to a region exposedfrom the through hole 32 a in a lower surface of the laminated iron core10, and extends in a horizontal direction of FIG. 5. The line segment P3corresponds to a region from the lower surface (inlet of the shaft hole10 a) of the laminated iron core 10 to the deformed part 10 c in theinner peripheral surface of the shaft hole 10 a, and extends in thevertical direction of FIG. 5.

The line segment P4 is a virtual line showing the boundary between aregion in which a detection signal of the non-contact sensor 38 reachesthe inside of the deformed part 10 c and a region in which the detectionsignal of the non-contact sensor 38 becomes a blind spot inside thedeformed part 10 c, and extends from an upper end point of the linesegment P3 to the left oblique upward side in FIG. 5. The line segmentP5 corresponds to an inner wall surface (upper wall surface) of thedeformed part 10 c, and extends in the horizontal direction of FIG. 5.The line segment P6 corresponds to a region of the side upper than thedeformed part 10 c in the inner peripheral surface of the shaft hole 10a, and extends in the vertical direction of FIG. 5.

Then, the controller 36 calculates a size of the deformed part 10 cbased on data of the surface profile P sent from the non-contact sensor38. The calculated size of the deformed part 10 c includes, for example,a height (length of the deformed part 10 c in the lamination direction)d1 of the deformed part 10 c, and a length d2 from the lower surface(inlet of the shaft hole 10 a) of the laminated iron core 10 to thedeformed part 10 c in the lamination direction.

The controller 36 calculates the height d1, for example, by obtaining alinear distance between an upper end point P10 of the line segment P3and a lower end point P11 of the line segment P6 based on the surfaceprofile P. The upper end point P10 is also a point of intersectionbetween the line segment P3 and the virtual line segment P4. The lowerend point P11 is also a point of intersection between the line segmentsP5, P6. The controller 36 calculates the length d2, for example, byobtaining a length of the line segment P3 based on the surface profileP.

In addition, when the peripheral edge of the blanked member 20 is rounddue to, for example, blanking by a punch (when a shear drop surfaceoccurs), the corner formed of the line segments P2, P3 is similarlyround, with the result that the length d2 may be calculated from a pointP12 of intersection between mutual extended virtual lines with the linesegments P2, P3 extended rather than the length of the line segment P3itself. Similarly, when the peripheral edge of the blanked member 20 hasprojections due to, for example, blanking by a punch (when burrs occur),the length d2 may be calculated from the point P12 of intersectionbetween the mutual extended virtual lines with the line segments P2, P3extended.

Then, with the laminated iron core 10 pinched by the pinching plates 30,32, the controller 36 sends a driving signal to the actuator 34, androtates the pinching plate 30 by the actuator 34 through the shaft 34 a.At this time, the laminated iron core 10 is pinched by the pinchingplates 30, 32, with the result that the laminated iron core 10 and thepinching plate 32 are also rotated with rotation of the pinching plate30 by the actuator 34. When the sending and receiving part for thedetection signal faces to the side of another deformed part 10 ctargeted for detection through the inlet of the shaft hole 10 a, thecontroller 36 sends a stop signal to the actuator 34, and stopsoperation of the actuator 34. Thereafter, the controller 36 acquires asize of another deformed part 10 c in a manner similar to the above.

(Action)

Incidentally, the shaft hole 10 a continuing in the lamination directionis generally small to the extent to which it is difficult for a contactsensor to enter the inside of the shaft hole 10 a, and the deformed part10 c of the inside of the shaft hole 10 a cannot be measured by thecontact sensor. However, in the embodiment, the non-contact sensor 38located in the outside of the shaft hole 10 a acquires the surfaceprofile P corresponding to a surface shape of the deformed part 10 cthrough the inlet of the shaft hole 10 a. As a result, the non-contactsensor 38 directly acquires the surface profile P of the deformed part10 c from the outside of the shaft hole 10 a without facing the deformedpart 10 c. Also, in the embodiment, the controller 36 calculates thesize of the deformed part 10 c based on the surface profile P. Thus, inthe embodiment, the size of the deformed part 10 c is directly acquiredusing the non-contact sensor 38 rather than the number of laminations ofthe blanked members 20. Consequently, the size of the deformed part 10 ccan be acquired with high accuracy.

Incidentally, a finished product of the laminated iron core 10 may beobtained by completely bonding the mutual blanked members 20 by weldingetc. with the laminated iron core 10 pressurized in the laminationdirection of the laminated iron core 10 after the laminated iron core 10is measured. Here, in the embodiment, in the case of measuring thelaminated iron core 10, the non-contact sensor located in the outside ofthe shaft hole 10 a acquires the surface profile P corresponding to thesurface shape of the deformed part 10 c through the inlet of the shafthole 10 a with the laminated iron core 10 pressurized in the laminationdirection of the laminated iron core 10. As a result, a size equal tothat of the deformed part 10 c in the finished product can be acquired.

In the embodiment, the sizes of the plurality of deformed parts 10 c arerespectively acquired by rotating the laminated iron core 10 withrespect to the non-contact sensor 38. As a result, since the laminatediron core 10 is rotated with respect to the non-contact sensor 38, thenon-contact sensor 38 acquires the surface profiles P of these aplurality of deformed parts 10 c at once when the laminated iron core 10is provided with the plurality of deformed parts 10 c. Consequently, thesizes of the plurality of deformed parts 10 c can be acquired at oncewith high accuracy.

Other Embodiments

The embodiment according to the present disclosure has been describedabove in detail, but various modifications may be made in the embodimentdescribed above within the scope of the gist of the present invention.For example, the controller 36 may calculate a width (length of thedeformed part 10 c in a circumferential direction of the shaft hole 10a) d3 of the deformed part 10 c as shown in FIG. 6 as information aboutthe deformed part 10 c. In this case, the controller 36 sends a drivingsignal to the non-contact sensor 38, and sends, for example, a detectionsignal diffused in a radial direction from the non-contact sensor 38,and the non-contact sensor 38 receives a reflected signal of thedetection signal and thereby, the non-contact sensor 38 is made toacquire a surface profile of the deformed part 10 c.

As shown in FIG. 7, the shaft 34 a may be connected to the non-contactsensor 38, and the actuator 34 may rotate the non-contact sensor 38through the shaft 34 a. That is, in the case of acquiring the surfaceprofile P of the deformed part 10 c by the non-contact sensor 38, withthe laminated iron core 10 pinched by the pinching plates 30, 32, thecontroller 36 may send a driving signal to the actuator 34, and theactuator 34 may rotate the non-contact sensor 38 through the shaft 34 a.

In other words, in the case of acquiring the surface profile P of thedeformed part 10 c by the non-contact sensor 38, one of the laminatediron core 10 and the non-contact sensor 38 may be rotated with respectto the other of the laminated iron core 10 and the non-contact sensor38. In the case of acquiring the surface profile P of the deformed part10 c by the non-contact sensor 38, one of the laminated iron core 10 andthe non-contact sensor 38 may be moved with respect to the other of thelaminated iron core 10 and the non-contact sensor 38 (displacement otherthan rotation may be performed).

Alternatively, the non-contact sensor 38 located in the outside of theshaft hole 10 a may acquire the surface profile P of the deformed part10 c through the inlet of the shaft hole 10 a while rotating one of thelaminated iron core 10 and the non-contact sensor 38 with respect to theother of the laminated iron core 10 and the non-contact sensor 38. Thenon-contact sensor 38 located in the outside of the shaft hole 10 a mayacquire the surface profile P of the deformed part 10 c through theinlet of the shaft hole 10 a while moving one of the laminated iron core10 and the non-contact sensor 38 with respect to the other of thelaminated iron core 10 and the non-contact sensor 38 (while performingdisplacement other than rotation). The number of rotations at this timemay be set at a proper value according to performance (for example, asampling rate) of the non-contact sensor 38.

As shown in FIG. 8, the non-contact sensor 38 may acquire a surfaceprofile of the projection 10 d of the inside of the magnet-insert hole10 b and the controller 36 may calculate a size of the projection 10 d.That is, the projection 10 d can also be said to be a deformed partpresent inside the magnet-insert hole 10 b. The size of the projection10 d calculated by the controller 36 includes, for example, a projectionlength d4 of the projection 10 d in addition to a height of theprojection 10 d, a length from a lower surface (inlet of themagnet-insert hole 10 b) of the laminated iron core 10 to the projection10 d in the lamination direction, and a width of the projection 10 dlike the deformed part 10 c.

In the case of acquiring the surface profile of the projection 10 d bythe non-contact sensor 38, the pinching plate 32 is provided with athrough hole 32 b larger than the magnet-insert hole 10 b in a placecorresponding to the magnet-insert hole 10 b. With the laminated ironcore 10 pinched by the pinching plates 30, 32, the through hole 32 bcommunicates with the magnet-insert hole 10 b. The non-contact sensor 38is arranged under the through hole 32 b of the pinching plate 32 so thata sending and receiving part for a detection signal faces to the side ofthe projection 10 d targeted for detection through the inlet of themagnet-insert hole 10 b.

As shown in FIG. 9, the deformed part 10 c may be a projected partprojected from an inner peripheral surface of the shaft hole 10 a towardthe radial inside (the side of the central axis Ax) like the projection10 d. In this case, the size of the deformed part 10 c calculated by thecontroller 36 includes, for example, the height d1 of the deformed part10 c, the length d2 from the lower surface (inlet of the shaft hole 10a) of the laminated iron core 10 to the deformed part 10 c in thelamination direction, the width d3 of the deformed part 10 c, and aprojection length d5 of the deformed part 10 c.

As shown in FIGS. 10 and 11, the deformed part 10 c may be a branchedhole radially continuing from the inner peripheral surface of the shafthole 10 a so as to be branched from the shaft hole 10 a. In FIG. 10, thedeformed part 10 c joins the shaft hole 10 a to the magnet-insert hole10 b. In FIG. 11, the deformed part 10 c is pierced from the shaft hole10 a to an outer peripheral surface of the laminated iron core 10. Thedeformed part 10 c may be a branched hole (not shown) continuing from aninside inner peripheral surface of the magnet-insert hole 10 b in theradial direction (the side of the central axis Ax or the side of theouter peripheral surface of the laminated iron core 10) so as to bebranched from the magnet-insert hole 10 b.

A plurality of places of one deformed part 10 c may be measured whilegradually shifting measurement places by the non-contact sensor 38. Inthis case, even when the deformed part 10 c has foreign substances suchas burrs, the size of the deformed part 10 c can be acquired with theforeign substances avoided by measuring the plurality of places of thedeformed part 10 c.

The deformed part 10 c may be measured by the non-contact sensor 38before the magnet-insert hole 10 b of the laminated iron core 10 isprovided with the permanent magnet 12 and the resin material 14 (thatis, in a state of only the laminated iron core 10), or after themagnet-insert hole 10 b of the laminated iron core 10 is provided withthe permanent magnet 12 and the resin material 14 (that is, in a stateof the completion of the rotor 1).

The hole such as the shaft hole 10 a provided with the deformed part 10c or the magnet-insert hole 10 b provided with the projection 10 d hasonly to be opened in one of the upper and lower surfaces of thelaminated iron core 10, and does not need to be a through hole. Thenon-contact sensor 38 may be provided over or under the hole at a sidewhich is open in order to send or receive a detection signal from thenon-contact sensor 38 through the hole.

The shape of the deformed part 10 c is not particularly limited. Thatis, the sizes of the deformed parts 10 c with various shapes can beacquired using at least the controller 36 and the non-contact sensor 38.

Also, the sizes of the deformed parts formed on the laminated iron coresconstructing the stator as well as the rotor may be acquired using atleast the controller 36 and the non-contact sensor 38.

Only for a purpose of reference, reference signs and numerals assignedto respective elements in this application are listed below.

-   1: ROTOR-   10: LAMINATED IRON CORE-   10 a: SHAFT HOLE-   10 b: MAGNET-INSERT HOLE-   10 c: DEFORMED PART-   10 d: PROJECTION-   20: BLANKED MEMBER (METAL PLATE)-   30, 32: PINCHING PLATE-   34: ACTUATOR-   36: CONTROLLER (CALCULATOR)-   38: NON-CONTACT SENSOR-   Ax: CENTRAL AXIS-   P: SURFACE PROFILE

What is claimed is:
 1. A method for measuring a laminated iron core,comprising: preparing a laminated iron core in which two or more kindsof metal plates with different shapes are laminated and a deformed partis formed inside a hole continuing in a lamination direction of thelaminated iron core; acquiring a surface profile data indicating asurface shape of the deformed part through an inlet of the hole by anon-contact sensor located in an outside of the hole; and calculating alength from the inlet of the hole to the deformed part in the laminationdirection by a calculator based on the surface profile data.
 2. Themethod according to claim 1, wherein the surface profile data indicatingthe surface shape of the deformed part is acquired by the non-contactsensor located in the outside of the hole through the inlet of the hole,with the laminated iron core pressurized in the lamination direction. 3.The method according to claim 1, wherein the non-contact sensor is anon-contact laser displacement meter, and the surface profile dataindicating the surface shape of the deformed part is acquired by thenon-contact laser displacement meter located in the outside of the hole,which applies laser light from the inlet of the hole to the deformedpart and receives reflected light of the laser light.
 4. The methodaccording to claim 1, wherein the deformed part is a projected partprojected from a peripheral surface of the hole in an intersectiondirection intersecting with the lamination direction.
 5. The methodaccording to claim 1, wherein the deformed part is a branched holecontinuing from a peripheral surface of the hole in an intersectiondirection intersecting with the lamination direction so as to bebranched from the hole.
 6. The method according to claim 1, furthercomprising: moving or rotating one of the laminated iron core or thenon-contact sensor with respect to the other of the laminated iron coreand the non-contact sensor.
 7. The method according to claim 1, whereina length of the deformed part in the lamination direction is calculatedby the calculator based on the surface profile data.
 8. The methodaccording to claim 1, wherein a length of the deformed part in acircumferential direction of the hole is calculated by the calculatorbased on the surface profile data.
 9. The method according to claim 1,wherein the deformed part is a projected part projected from aperipheral surface of the hole in an intersection direction intersectingwith the lamination direction, and a projection length of the projectedpart is calculated by the calculator based on the surface profile data.10. The method according to claim 2, wherein the non-contact sensor is anon-contact laser displacement meter, and the surface profile dataindicating the surface shape of the deformed part is acquired by thenon-contact laser displacement meter located in the outside of the hole,which applies laser light from the inlet of the hole to the deformedpart and receives reflected light of the laser light.
 11. The methodaccording to claim 10, further comprising: moving or rotating one of thelaminated iron core or the non-contact sensor with respect to the otherof the laminated iron core and the non-contact sensor.
 12. The methodaccording to claim 2, further comprising: moving or rotating one of thelaminated iron core or the non-contact sensor with respect to the otherof the laminated iron core and the non-contact sensor.
 13. The methodaccording to claim 3, further comprising: moving or rotating one of thelaminated iron core or the non-contact sensor with respect to the otherof the laminated iron core and the non-contact sensor.